Method of producing tea free from theine



Patented Aug. 13, 1935 UNITED STATES PATENT OFFICE METHOD OF PRODUCINGTEA FREE FROM THEINE Theodor Grethqflamburg, Germany No Drawing.Application November 14, 193:,

Serial No. 698,015. In Ge 1932 rmany November 17,

3 Claims. (Cl. 99-8) exceed a temperature of 65 centigrade, the

treatment being interrupted by moistening the tea leaves with water,which may be done once or several times.

It has been found now that the aroma of tea treated in the mannerdescribed can be considerably improved by exposing the tea for a shorttime, amounting approximately to 5 to 8 minutes, to the action of watervapor while the temperature limit for the tea remains. about 65centigrade, and, preferably, the temperature is kept at 50 to 52centigrade.

This water vapor treatment may take place after the solvent has beeneliminated from the tea by the passage of air having room temperature orof heated air or of another gas.

It is still more advantageous to draw of! the extraction agent from thetea after extraction, as a high temperature of the tea can better beprevented in this'manner. There will then be 1 kg. extraction agent for1 kg. tea. Steam is then passed through for 5 to 8 minutes and thelargest portion of the extraction agent removed with the steam which,simultaneously, has an aromatizing effect upon the tea. The next step isthe drying of the soaked tea by means of warm air, as described in theco-pending application mentioned.

Treatment with .water vapor may be eifected also in the vacuum. Themethod can be further improved by cooling the tea after the extractionand the passage of steam by blowing through cold air for 5 to minutes,whereupon this moisturecontaining tea is dried in vacuum at 65 to 10centigrade without passing more air therethrough, which requiresaboutone and a half hours. I

The invention can be applied for example by extracting the tea leaves,moistened with water at room temperature or while slightly heating thesolvent, by means of methylene chloride until the theine content amountsto approximately 0.1%,

which will be the case after 2% to 3 hours. The 10 solvent is thendrained oil from the leaves and expanded steam of 100 centigrade blownthrough for about 2% minutes until the temperature thereof is about 55centigrade at discharge. Then warm air having room temperature is passedthrough for 5 to 10 minutes whereupon drying in vacuum takes place, sothat heating of the tea does not exceed 65 to 70 centigrade. .Drying iscompleted after approximately one and a half hours. I

I-claim: 1. A method of producing tea free from theine by subjectingmoistened tea to extraction with a theine solvent, and then treating thetea at a temperature not exceeding about 65 centigrade u with watervapor. 2. A method of producing tea tree from theine by subjecting themoistened tea to extraction wlthf theine solvent, and then treating thetea under redpcedn s ure and at a temperature not exceeding 'abeyutW-centigrade with water vapor. 3. A method of producing tea freefromtheine by subjecting the moistened tea to extraction with a theinesolvent, draining of! the solvent,

blowing water vapor at a temperature of 100 centigrade through the massuntil the temperature th reof at discharge is about centigrade, passingair through the mass and drying the tea under reduced pressure in such amanner that the temperature of 'the tea does not exceed about 40centigrade. k

' THEODOR GRETHE.

